I've got a '54 Chevy Bel-Air 4 door. It weighs 3,400 lbs. I was running the 260M, 221 degrees @ .050", .429" lift. Valves set at .018"
The setup:
The original 235 was bored .030", '54 head shaved .030", Clifford water heat intake, Holley 390, fenton headers, 2" exhaust w/glasspacks, 'mini' HEI, hardened exhaust seats, dual-wound valvesprings, Manley SS valves, flattop pistons w/ .025" deck height.
8:1 compression.
3-speed standard with 3:55 rear cogs.
I ran the clifford cam with the stock 1bbl rot-pot and single exhaust. Then I installed the 4bbl/duals setup. I had a fairly noticable loss in power below 2,000 RPM with the 4bbl and duals. This is due to the air velocity thru the 4bbl at low-rpm, intake charge reversion, reduced low-RPM exhaust scavaging velocity with duals, and the loss in cylinder pressure due to the increased valve duration/overlap with the Clifford cam.
At mild street driving it wasn't a problem. 2nd gear at low RPMs did kind of suck. If I wanted to really take off from 1st, the car didn't really start to pull until 2 grand, or about 15 MPH. It had a really mean lope, it would idle about 700-800 rpm with a RUMP-BLAT-RUMP-BLAT-RUMP-BLAT that I loved.
This motor ran from '97 to '01. The crank journals weren't machined correctly. After 4 years of running it hard, the #3 main failed. As Richard Pryor said: "The motor said f**k it and fell out."
Compare the cam you're gonna use with the one I listed above. I really think that if you use a cam with more than 220 degrees duration, you're going to be unhappy with the lower RPMs. I'm going with a milder cam this time from another vendor, and raising my compression.
There are also some issues with aftermarket valvesprings, retainers and such, but its worthy of another thread.
good luck
chip
